Top 10 PCB Layout Best Practices & Insider Tips

While engineers often pay close attention to circuits, cutting-edge components, and coding while working on an electronics project, the PCB layout is often overlooked. Issues with functionality and reliability can stem from bad PCB layout. If you're working on a PCB design in a business or lab, you need to carefully follow several rules. Here are our ten PCB layout best practices.

How to Design a PCB

There are several different steps involved in the PCB design and development process. Developing a circuit that can quickly carry out complex tasks requires careful attention to each of these steps. 

The first step in making PCB is deciding on its materials and physical structure (layering and stacking). The next step is to place the components and route the traces based on how they are distributed throughout the different layers. 

We'll elaborate on that final aspect and give you some advice that should make your routing simpler and allow you to prevent some common mistakes. If you follow these guidelines, routing could be a highly skilled and satisfying part of the PCB design process. The first step is deciding on the schematics.

Schematics

The electrical schematic is a crucial part of any project. Here, we'll use PCB design software to sketch out the circuits our board prototypes. It's always better to have PCB design software or at least partner with a reliable third-party PCB design business that offers PCB layout services. Since they offer custom development services, you don’t have to worry about any compatibility issues and you save money because you won’t have to pay for features that you won’t use. 

Using this program, you can see how your electrical diagram is laid up and catch any mistakes before you commit them to paper. Because the PCB layout depends on the electrical diagram design, any mistakes made here will affect the final product.

Board Size & Shape

PCB layout design begins with the dimensions and shape. The size of the finished electronic product usually defines the size of the bare board, and the available space decides whether or not all the necessary components can be installed. A multi-layer or high-density-integrated (HDI) layout is a good option if you're strapped for room. 

Therefore, it is essential to make a rough board size estimate before beginning the design process. The second factor is the PCB's physical form. While most printed circuit boards (PCBs) are rectangular, the arrangement of components may be significantly affected by other board shapes used in certain devices.

Space matters

Nowadays, every centimeter of a circuit board can hold more parts than ever before. That's a great thing for consumers. More parts on a board means more features and use for the gadget. But, designers may have a hard time zeroing in on the optimal solution for their consumers.

As more parts are added to a board, space becomes more limited. Component spacing is crucial and should never be ignored. Without enough spacing, there will be nowhere to conceal the cables. Many parts also generate heat, which becomes more of an issue as board densities increase.

You can avoid this by optimizing the component placement.

Consider the Placement

Component arrangement order is a vital factor in PCB design and layout. To cut down on time and materials used for assembly, it helps to have a good system in place for keeping track of where each component is located. Here are three tips:

1. Put the most essential items first. Sometimes the physical container has size limitations that determine where certain components must be installed. It is a good idea to position and secure these parts before moving on to the other parts of the arrangement.
2. Set up the main CPUs and ICs. High-pin-count ICs and processors, for example, often need to communicate with several other parts of the design. When designing a PCB, it is simpler to route traces to these components if they are placed near the center.
3. Be careful about the nets. Unrouted nets are often obvious when components are inserted in a PCB layout. The fewer nets that intersect, the better. At every point where two networks meet, you can use Vias to connect the two layers. Using strategic component placement to avoid net crossings makes it simpler to follow the recommended routing practices for a PCB design.

Control the Heat

When in use, many electronic parts generate significant amounts of heat. You need to watch out for heat-sensitive components like thermocouples and electrolytic capacitors. Temperature readings may be inaccurate if thermocouples are placed too near to a heat source. Electrolytic capacitors have a shorter lifespan when placed near heat sources. 

One solution is to put rectangular copper sections beneath the IC. By doing so, you protect the CI from overheating and extend its useful life.

If you want the PCB layout to be secure, you should keep temperature-sensitive components away from parts that generate a lot of heat and put them in the cooler areas of the board.

Create a Ground Plane

Every PCB needs to have a ground plane so that voltages can be measured with a common reference. On the other hand, if you decide to ground each trace separately rather than connecting them to a single ground plane, you'll have a large number of connections with different values of resistance.

If you're working with multiple layers, the easiest option is to establish a solid ground plane, which may be a whole copper region. A ground plane placed underneath signal-carrying wires may lower their impedance and increase their resistance to noise. 

The power and ground planes should be on the center of the bottom layers while maintaining symmetry. This safety measure prevents the board from bending and deforming or partially detaching the components.

Choose the right tool

The first step in getting the most out of PCB designing software is picking the one that fits your specific needs. The design's detail, the software's features, interoperability with other programs and devices, and pricing are just a few of the many things to think about. Make sure the tool you choose has a solid customer service and update structure, as well as an intuitive interface and an extensive set of parts and symbols.

Of course, by hiring third-party experts in PCB design in the UK, you can get tailored hardware development services that exactly match your budget and needs. It’s more affordable to get PCB design services this way because you don’t deal with a ready-made solution with excessive features.

Here’s a short list of PCB software programs that are widely popular on the market:

• Eagle
• Altium
• Allegro
• ProteusKiCad

Don’t Forget the Thermal Pads & Vias

When wave soldering items with a high level of copper or multilayer PCBs, thermal pads are an absolute need. Using thermal pads on through-hole parts is a great idea for better cooling as it promotes easier soldering and better heat dissipation. 

A thermal pad should be used wherever a hole goes through a ground or power plane. In addition to providing a power link between layers, thermal vias are great tools for hardware (peripherals) that can dissipate the heat from the warmest parts of a device to the surrounding air. Thermal vias sitting underneath a chip footprint reduce the temperature, which in turn increases the circuit's stability and lifespan.

Silkscreening is Key

Silkscreening is the process of printing text and images directly onto a PCB. Use this space to include any text, images, or logos that will appear on the PCB, such as PINs, serial numbers, and identifiers.

Making a smart choice about silkscreening may improve the device's useful life. Using proper silkscreening techniques, you may make life easier for yourself and anybody else who handles the board.

It's not uncommon to discover unanticipated problems in your PCB design lab when applying labels to your silkscreen layer. Using a silkscreen on each side of the PCB is a good way to speed up assembly.

Maintain Signal Quality

The PCB layout is a crucial factor in determining the quality of your signals and their strength against potential RF interferences. Parallel traces will have greater interference and create many issues, so it's best to avoid spreading them out that way when trying to improve signal quality. To further minimize capacitance and mutual inductance, tracks should intersect only at right angles if absolutely necessary. 

Where to Go From Here

As we said in the beginning, you can use a ready-made PCB design software program to go through all the steps and create the right layout with enough spacing and minimal heating. Of course, if you don’t have an expert on your team, it’s much wiser to hire one of the reliable PCB design companies in the UK because they offer customized embedded development services that are tailored to your specific budget and don’t cause any issue with compatibility. 

FAQ

What is a Good PCB Layout Design?

You should always maintain the power and ground planes on the inside of your PCB. To keep your board from bending and bending, make sure they're centered and symmetrical. Components may shift out of place or be damaged if the board bends.

How Many Layers Do I Need?

Multilayer printed circuit boards typically contain between four and eight layers. Smartphones may contain as many as 12 levels, depending on the complexity of the application. Moreover, designers choose even layers over odd ones since they don't create an unnecessarily complicated and problematic circuit when laminating the layers.

Why is Space Vital in PCB Layout Design?

It's a smart move to prepare the PCB with extra room in case new components (or replacements for the existing ones) are required in the near future. It is absolutely possible to exclude these auxiliary parts before production if they end up being unnecessary.

How Long Does it Take and How Much Does it Cost?

Designers use PCB software to create the PCB layout. The PCB layout design process will become more difficult and time-consuming if certain kinds of designs like custom wireless design are in the mix.